Extension Master GardenerSM Volunteers of Buncombe County

Soils & Fertilizers

Soil Tests: What They Tell You and What They Don’t!

“Have you done a soil test?” is one of the first questions Extension Master Gardeners ask if you’re starting a new gardening project. Do you know what a soil test can tell you—and what it can’t?

Soil Test Box and Sample Information Sheet

Useful information from soil tests:

  • Nutrients your plants need to grow
    • Primary macronutrients: Nitrogen (N), Phosphorus (P), and Potassium (K)
    • Secondary macronutrients: Calcium (Ca), Magnesium (Mg), and Sulfur (S)
    • Minor nutrients: boron, chlorine, copper, iron, manganese, molybdenum, nickel, and zinc
  • Soil acidity level (pH)

Your soil test will tell you the amount and type of fertilizer to use to provide the nutrients your plants need and how to adjust the soil pH to the appropriate level. It can also tell you if you have too much of certain nutrients! Overfertilizing can be as detrimental to your plants’ growth as too little fertilizer.

 Your soil test won’t tell you if you have:

  • Poorly structured soils
    • Plants may have difficulty getting established on sites where topsoil was stripped away, or soil layers were disturbed and/or compacted during construction.
    • Heavy clay soils, in particular, are difficult for roots to penetrate.
  • Too much or too little soil moisture
    • Poorly drained soils may prevent plant roots from getting enough oxygen.
    • Drought or fast-draining soils may lead to root damage/death from too little soil moisture.
    • Watering too frequently or not deeply enough can create moisture problems for plants in good soils.
  • Plant competition
    • Shallow tree roots or the roots of plants spaced too closely may compete for soil nutrients.
    • Allelopathic plants—such as walnut trees—may act as herbicides and keep nearby plants from thriving.
    • Shade from other plants may inhibit growth of sun-lovers.

So, knowing the proper nutrients and soil pH is a start, but having your plants thrive means making sure your soil has appropriate soil structure and moisture, and providing them with appropriate space and plant companions.

Article by Debbie Green Buncombe County Extension Master GardenerSM Volunteer

For more information:

 Soil testing in North Carolina:

https://content.ces.ncsu.edu/extension-gardener-handbook/1-soils-and-plant-nutrients#section_heading_7241

 “What a Soil Test Does Not Tell You” (scroll down to last article in this newsletter):

https://hnr.k-state.edu/extension/info-center/newsletters/2018/Feb20_2018_7.pdf

Allelopathy in walnut trees:

https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/430/430-021/430-021_pdf.pdf

 

 

 

Outdoor Composting: Make Black Gold for Your Garden

It’s that time of year when leaves are falling! We gardeners have choices: let the leaves remain where they’ve dropped; use them elsewhere in our landscapes; rake, bag and drag them to the curb to be added to the landfill; burn; or compost them.

Although the City of Asheville collects bagged leaves, in much of Buncombe County you must bring bags to the landfill and pay a fee. Our landfills are becoming increasingly full, made up of 20% to 30% food scraps and garden waste, according to the EPA. Burning is not permitted in the city. The county allows burning of yard waste only at designated days and times, and where there is no public trash pickup. Depending on your location, you may need a permit!

Pile of Leaves_Compost_Jeremy Noble_CC BY 2.0_Flickr
Leaves ready for compost heap

If you aren’t using leaves elsewhere in your yard, start a compost heap and make “black gold” for your garden!

Advantages of composting
Compost is the material that results from the decomposition of biodegradable materials. Composting is easy, doesn’t add to the landfill, enriches the soil while helping retain moisture, and reduces the need for chemical fertilizers. 

It’s all about the soil. Composting replenishes soil nutrients that help plants grow, slowly releasing major nutrients (nitrogen, phosphorous, potassium) for gradual use by plants. It loosens clay soil and helps sandy soil retain moisture. Use compost as a mulch at the base of plants, or dig it into the soil when planting. Compost is an ideal soil amendment for gardening uses.

Composting “do’s”
It can take from 3 months to a year to produce good workable compost, depending on the method used and how often it is turned. A composting area is ideally located in a semi-shady, level place which will be convenient to use, but is over 6 feet away from your house.

A compost pile is made of roughly equal proportions of “green” and “brown” materials with enough water to keep things damp and ready to decompose. Greens are nitrogen-rich ingredients such as vegetable and fruit scraps, coffee grounds, egg shells, and grass clippings. Browns are carbon-based materials, such as dead leaves, branches, and twigs. You can include newspaper, but make sure it does not exceed more than 10 percent of the total weight of the material in the compost heap.

Layer greens and browns in roughly equal proportions, moistening the pile as you go. The materials will compost more quickly if they are chopped into small pieces. Turning the layers periodically will speed the breakdown process.

Composting “don’ts”
Some materials just won’t work in an outside compost pile:

  • Animal products such as meat or bones, grease, or dairy products. These can attract rodents.
  • Dog feces or similar waste that may contain parasites.
  • Diseased plants or plant material that have been treated with pesticides or herbicides.
  • Glossy magazines often have toxic pigments and should not be used.
  • Orange peels and other citrus rinds, corn cobs, and nut shells which break down very slowly.
  • Any plants that contain intact seed heads.

Composting structures
If you don’t want a simple compost heap, you can use a variety of compost structures. One is a circular ring of closely woven metal fencing material about 4 to 5 feet in diameter with chain clips for fasteners. These can be unsnapped for ease in turning the pile.

A very user-friendly method is the three-bin structure, which uses a kind of assembly-line process. Place three bins next to each other in a row. Make each 3- to 5-foot square bin of sturdy fence wire, held in place with either metal or rot-resistant wood posts. Using removable slats in the front of each bin keeps the area tidy, while allowing easy access to turn the compost. Start the fresh material to be composted in the first bin. Turn it into the middle bin after a few days of “cooking,” and put a fresh batch in the first bin. Finally, move the middle material to the third bin until it is finished compost and ready to use.

Plastic drums which rotate are also available. While they make turning the compost easy, the drums can get heavy and hard to turn when full.

The finished product
Your compost is ready when it is dark brown, has a light and crumbly texture similar to potting soil, and has a pleasant earthy scent. It takes just a little effort to do so much good for your soil and for our environment!

Learn more
Extension Master Gardener Handbook: Composting
https://content.ces.ncsu.edu/extension-gardener-handbook/2-composting

Western North Carolina Regional Air Quality Agency: Open Burning Rules
https://www.buncombecounty.org/common/WncAir/burning/burning-pamphlet.pdf

Article written by Sally Wheeler, Extension Master GardenerSM Volunteer.

“Composting” Indoors? You Don’t Need Worms Anymore!

Do you have limited garden space, bear problems, or other reasons that make outdoor composting problematic? If you want to avoid throwing away food scraps, indoor “composting” is not limited to worm bins (vermicomposting) or expensive electric composting appliances.

Bokashi bucket with comfrey_Fluffymuppet_CC BY-NC-ND 2.0_Flickr
Bokashi indoor composting bucket

Enter Bokashi
Bokashi is based on Asian gardening practices and differs from traditional composting in many ways, in that it:

  • Is an anaerobic (“in the absence of air”) process that you can complete indoors.
  • Requires a closed container.
  • Requires the addition of microbes.
  • Requires minimal attention (draining of accumulated liquid).
  • Takes only about two weeks to complete once the container is filled.
  • Results in a fermented product that you bury in the garden rather than a finished compost.

Although the process has a long history, Japanese horticulture professor Teruo Higa developed several microbial products marketed as “Effective Microorganisms” (EM) that have made Bokashi more widely known and more readily available in North America.

How it works
If you purchase a container and microbe-treated bran, you need only start adding your kitchen waste—including meat and dairy products—to the container in batches, sprinkling with bran, and compressing the material each time you make an addition, then seal the container. Purchased containers include a spigot for draining off leachate every few days. You may see a white mold forming in the container when you add scraps, but this is normal. You just continue adding more scraps, sprinkling on your microbe-containing bran, and compressing the material.

Bokashi Composter_George Morris_CC BY-NC-ND 2.0_Flickr
Draining off leachate from Bokashi indoor composter

You may want more than one container if you want to continuously dispose of scraps, although you can freeze accumulating kitchen waste while your full container completes fermenting.

You can construct your own container and prepare your own bran products to save money, but this will require more effort and time. Although the process is beyond the scope of this blog, Bokashi Composting: Scraps to Soil in Weeks by Adam Footer, published by New Society Publishers in 2013, provides information on producing your own bran.

Once the sealed container is full, you need to leave it for no more than 2 weeks to finish fermenting. You will then have a product that looks much like what you put into the container—but with a sour pickled smell. This product will break down very quickly in the garden, but needs to be buried under several inches of soil to avoid attracting animals.

Pros
If you want a relatively compact, low-maintenance way to dispose of kitchen scraps, Bokashi is the way to go!

  • Disposing of dairy and meat scraps for use in the garden is a real advantage.
  • The bucket is odor-free except when you are making additions, and the smell of fermentation when you open the container or drain off leached liquids is not overpowering or unpleasant.
  • You can leave the container unattended for short vacations.
  • You can store completed materials until burial outdoors.

. . . and Cons

  • The up-front expense of containers and treated bran may be prohibitive, although certainly competitive with indoor composting set-ups (vermicomposting or electric appliances).
  • You need new or “fallow” space in your garden for burying the fermented waste.
  • You must dig a hole to use the finished product.
  • You will need to wash out the container for re-use.
Food for Good HK_IMG_2545_CC BY-NC 2.0_Flickr
Bury composted kitchen waste in the garden and improve the soil.

The verdict?
Research is ongoing about the value of Bokashi products in the garden. The leachate is sometimes touted as fertilizer. It is likely to contain phosphorus and potassium, but not nitrogen! You can simply discard this if you don’t want to try it on your plants. Research on the use of EM to produce compost suggests that in addition to speeding up the process, it can increase nutrients.

If conventional composting is not an option and you have space to bury your completed Bokashi fermentation, consider this method as an alternative to throwing away your kitchen scraps or waiting on buried scraps to decompose.

Article written by Debbie Green, Extension Master GardenerSM Volunteer.

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Buncombe County Extension Office
49 Mount Carmel Road
Asheville, NC 28806
Helpline 828-255-5522

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